1. Field of the Invention
The present invention relates to implant devices for replacement of amputee limbs; and more particularly to replacement of amputee limbs with a percutaneous implant device that physiologically loads both bone and soft tissue.
2. Description of the Prior Art
Many patents address issues related to implant devices that attach to amputee limbs. These devices typically carry features that facilitate attachment of prosthesis to the implanted device. Some of the implanted devices have a hinge present within the implanted device to function as a knee or elbow joint. One of the devices has an extension that attaches to the Achilles tendon, to provide a connection having a skin attachment. The attachment of the bone to the implant is accomplished through use of a methacrylate or appetite adhesive, or by using a thin layer of porous body, such as netting. There is no disclosure or suggestion concerning a device capable of biologically bonding the implant to the bone while, at the same time, creating biological attachment of soft tissue and skin, which thereby provides a continuously bonded structure that resembles a natural bone with entirely bonded skin and soft tissue.
U.S. Pat. No. 3,947,897 to Owens discloses an apparatus for connecting a prosthesis to a bone. This apparatus is used to connect a prosthesis to a bone of a stump of an amputated limb such as the arm or leg of a person. The apparatus includes a tubular female socket adapted to be inserted within an intermedullary cavity of the bone. The tubular socket has an open lower end with a sleeve of bio-compatible material permitting access through the skin of the amputee's stump. A stainless steel, tubular socket having a roughened outer surface is fitted into a bone canal, and the exposed end of the sleeve is covered with a biocompatible material, over which the skin is extended to heal the skin attachment. There is no bond between the free end of the inserted socket and the sleeve of biocompatible material. Stainless steel does not allow in-growth of bone. Even though the skin may be attached to the porous sleeve, the lack of connection between the socket and the sleeve prevents the skin from being attached in the same manner as the bone. The latter has practically no bone in-growth, just forced fit. The tubular sleeve has attachment hardware for securing an externally inserted prosthesis.
U.S. Pat. No. 4,143,426 to Hall et al. discloses a permanently attached artificial limb. This permanently attached artificial limb comprises an endoprosthesis in combination with an artificial tendon attachment. The artificial tendon attachment permits the use of existing skeletal muscles to power external articulating mechanical joints of the endoprosthesis device. The artificial tendon penetrates the skin and provides a strong interface with existing skeletal muscles. This implant has a porous polymethyl methacrylate bond between the bone and the intramedullary rod and this cemented bonding procedure does not result in bone in-growth. The open end of the intramedullary rod is covered with velour fabric, e.g. of nylon or Dacron, to allow skin attachment at the skin interface. There is no direct bond between this velour fabric and the intramedullary rod. Therefore, this device does not attach the bone tissue to the intramedullary rod by bone in-growth. It also does not attach any portion of the implant that connects the intramedullary rod to soft tissue by tissue in-growth. An artificial tendon is attached to a velour covered silicone (Silastic) ball, which in turn is connected to a velour sheath, which is attached to the stub of the Achilles tendon to allow muscle directed movement of the prosthesis.
U.S. Pat. No. 4,158,895 to Reswick et al. discloses a prosthesis coupling. A stainless steel socket is inserted into a bone cavity and bonded with methylmethacrylate creating a cemented bond that does not result in bone in-growth. One end of a silicone flexible coupling is attached to the socket, and the other end of the silicone coupling is connected to a vitreous carbon sleeve. The skin is stitched over the vitreous carbon, allowing skin attachment. The skin seal thus created at the sleeve is not broken when the user moves an implant inserted into the sleeve due to the flexibility of the silicone coupling which essentially floats the skin seal. The skin or soft tissue attachment does not work in coherence with the movement of the bone, owing to the flexibility of the coupling. The attachment of the bone to the implant is only accomplished through a cement bond. Accordingly, there is no bone in-growth.
U.S. Pat. No. 4,881,536 to Noble et al. discloses a method and apparatus for prosthesis placement. This surgical procedure is for orthopedic implantation of prosthesis. Cobalt chromium or stainless steel prosthesis is placed in a bone cavity that is filled with a viscous polymer that hardens to permanently attaché the prosthesis to the bone cavity. There is no bone in-growth between the prosthesis and the bone. There is no attachment of the soft tissue to the prosthesis.
U.S. Pat. No. 5,041,137 to Nemoshkalov discloses a method for prosthetic restoration of human limbs. This device for prosthetic restoration of human limbs comprises a supporting member for the stump, shaped as a spherical bowl and connected to the prosthesis of the limb missing portion, and a fixing contrivance interconnecting the stump bone and the supporting member. The supporting member is made of a material indifferent to living tissue and its diameter corresponds to the stump outside diameter. This device has a tapered rod that is inserted into a bone cavity that is bonded using an acrylic resin binder that hardens in 5-7 minutes. There is no bone in-growth joint between the inserted rod and bone tissue. A support body with a porous surface coating is attached to the inserted rod by a threaded screw. The top outer surface of the supporting member, which is made of a porous material, only serves as a support for the stump bone, which contacts the bone in a very limited area. Bone in-growth in this limited region is negligible, causing the implanted taped rod to be predominantly held in place by the acrylic resin. The top surface of the porous supporting member contacts the soft tissue and muscles providing soft tissue in-growth. The skin is merely wrapped around the porous support member, which provides soft tissue in-growth attachment. This device does not provide simultaneous in-growth of both bone and soft tissue.
U.S. Pat. No. 5,169,597 to Davidson et al. discloses a biocompatible low modulus titanium alloy for medical implants. This biocompatible titanium alloy has low elastic modulus and contains titanium, with about 10-20 wt. % or 35-50 wt. % niobium and up to 20 wt. % zirconium useful for fabricating of orthopedic implants. More typically, the alloy is 74% Ti with 13% of each of Zr and Nb. The modulus of elasticity of the alloy is typically 84 GPa, similar to a bone modulus of elasticity. The alloy has high strength, typically greater that 979 MPa. Portions of the implant may be coated with porous bead or wire mesh coating.
U.S. Pat. No. 5,181,928 to Bolesky et al. discloses a modular hip prosthesis. This modular hip prosthesis is provided for the replacement of a portion of the femur. The prosthesis is assembled from a kit that includes a stem member having an upper portion and a lower portion, with the lower portion sized to be received in the femur. The kit also includes a body member that is sized to replace a portion of the femur and is configured to be received over the upper portion of a stem member. The kit also includes a head member that is sized to replace the head of the femur. A neck member is provided to attach the head member to the body member to form an assembled prosthesis. The modular hip prosthesis has a central stem that is bonded to the bone by a grouting material or bone cement material. There is no bone in-growth attachment of the central stem and the bone. The soft tissue is not attached to the implanted stem. Soft tissue is not attached to the body member that is attached to the upper portion of the stem to attach to a prosthesis.
U.S. Pat. No. 5,571,193 to Kampner discloses an implant with a reinforced resorbable stem. This prosthetic implant for a bone joint has an anchor formed of a resorbable sleeve reinforced with a nonresorbable core. The implant has a central non-absorbable metallic core surrounded by an anchor made from a resorbable material. The anchor creates an interference fit between the implant and the bone cavity and slowly disintegrates as the bone ingrowth occurs. At this point, the central metallic core becomes detached and no longer carries any load, allowing the bone ingrowth to carry all the loading. This method creates a dangerous situation when the implant is first incorporated, since the metallic core is not in any manner attached to the anchor. Moreover, the ingrowth of the bone into the anchor progressively destroys the integrity of the resorbable layer, while the bone structure is yet to be built completely for load sharing. The presence of a non-load carrying metallic core reduces the overall cross section of the bone, reducing its load capacity. There is no bone in-growth attachment connecting the bone to the metallic core. All of the load must be accommodated by the resorbable material with some bone in-growth.
U.S. Pat. No. 6,197,065 to Martin et al. discloses a method and apparatus for segmental bone replacement. This bone attachment assembly is for reattaching of a remaining portion of a long bone diaphysis following resection. The assembly includes a main body, an anchor for anchoring the device with respect to the remaining bone portion and an attachment portion for attaching the main body to the anchor. The assembly may be connected to an orthopedic appliance, an interposed orthopedic appliance connected to a second bone attachment assembly, or a transcutaneous bar for attaching an external appliance. The first portion of the broken bone is milled to a preselected convex conical geometry. The main body of the implant is milled with a concave conical geometry and coated with bone in-growth material. The central portion of the implant has a tapered section. It is inserted into the bone canal. A cylindrical section thereof fits against the bone and is said to prevent lateral movement. There is no bone in-growth in this cylindrical region of the implant. The implant has a central aperture that has a threaded compliant connecting rod that is screwed into the implant on one side. The distal side of the connecting rod is placed within the bone cavity and is anchored by a plurality of transverse anchor bodies. Due to this compliancy of the connecting rod, the implant is only held by the fit at the cylindrical region. It awaits bone in-growth at the conical portion, which takes substantial time. The compliant rod provides no support since it is said to be compliant. There is no provision in this device for soft tissue in-growth.
U.S. Pat. No. 6,425,925 to Grundei discloses a leg exoprosthesis for adaptation to a thigh stump. This leg exoprosthesis is appointed for adaptation to a thigh stump, and has an adapter for a knee joint. The knee joint is mounted and coupled to a lower leg prosthesis. A bridle band force-transmitting element is coupled to the lower leg prosthesis for introducing extending forces. This device is a replacement for a knee joint having one end attached to the broken bone. The connection to bone does not have bone in-growth provisions. The stump portion is merely sealed with no provision for soft tissue in-growth.
U.S. Pat. No. 6,464,728 to Murray discloses a modular neck for femur replacement surgery. This prosthesis is provided for femur replacement surgery. It has a stem, which is received in the femur. A modular neck is removably attached to the stem so that its angle of protrusion can be customized by the surgeon. The stem passes through a sleeve inserted into the bone canal, which has a press fit with respect the bone cavity. Thus, the implanted stem does not directly contact the bone cavity. A sliding movement of the sleeve allows for micro-motion, redistributing stress at the implanted location. The stem does not have a bone in-growth coating, and these micro-motions will result in poor bone in-growth. Also there is no provision for soft tissue in-growth attachment.
U.S. Pat. No. 6,482,238 to Grundei discloses an upper leg stump endoprosthesis for an exoprosthetic provision. This upper leg stump endoprosthesis is designed for an exoprosthetic provision of a patient having undergone above-knee amputation. The upper leg stump can be inserted into a shank to which a below-knee prosthesis with a foot part is fitted. The prosthesis includes a proximal shaft, which is implantable in a truncated femur. An open-mesh, three-dimensional netting structure covers at least partially the proximal shaft. An adapter is connected to a distal end of the proximal shaft. A substitute condyle element, constituting a replica of a natural condyle of a knee joint, is linked to said shaft by the adapter. The resulting device comprises a knee joint that is attached to the stump bone. The attachment includes a mesh that surrounds the insertion stem and is said to promote bone in-growth. There is no attachment of soft tissue by in-growth. Moreover, the attachment of the bone tissue with the stem is questionable, since there is no physical bond between the net and the stem.
U.S. Pat. No. 6,485,522 and Foreign Patent Application No. WO 9965426 to Grundei disclose an adapter for an exoprosthetic standard element. This adapter is for an exoprosthetic standard element such as an exoprosthetic knee joint. The adapter can be inserted with a proximal handle part into a tubular bone stump. The proximal handle part is at least partly covered with a three-dimensional open-loop network structure, and at its distal end has a coupling device for the standard element. The device has a stem that is inserted into a bone canal. The stem has a coating of an open-mesh, three-dimensional space-network structure, through which bone materials can grow. There is no attachment of soft tissue permitting soft tissue in-growth.
U.S. Pat. No. 6,494,918 to Pope et al. discloses a component for a prosthetic joint having a diamond load bearing and articulation surface. The prosthetic joint comprises a substrate that includes a solvent-catalyst metal, a diamond layer sintered to said substrate. A zone between the substrate and the diamond layer has a composition gradient of decreasing solvent-catalyst metal content across the zone. The chemical bonds in the zone include chemical bonds including diamond-to-diamond bonds in the diamond table, diamond-to-metal bonds in the gradient transition zone, and metal-to-metal bonds in the solvent-catalyst metal. A mechanical grip between said diamond layer and the substrate tends to secure the diamond layer to the substrate. The load bearing surfaces where movement occurs such as a ball joint have a polycrystalline diamond coating to reduce friction and wear. The disclosure of the '918 patent does not suggest inserting and attaching an implant.
U.S. Pat. No. 6,843,808 to Grundei discloses subcutaneous, intramuscular coupling for a rigid transcutaneous implant. This subcutaneous, intramuscular bearing is for a rigid transcutaneous implant that can be anchored intracorporeally in a bone stump. The implant has an extracorporeal coupling device for a standard exoprosthetic component that includes a flexible material, and that has a socket that distally surrounds the implant in a firm manner. The bearing includes an enveloping sheath arranged intracorporeally in the form of a flexible pleated bellows. The sheath is proximally connected to the socket via a collar that is formed in a sealing manner. Formation of the collar is such that a hollow space with a minimum breadth s remains free between the inner walling of the pleated bellows and the outer walling of the socket. A flexible grid network is arranged distally at the pleated bellows. An additional grid network adjoins the flexible grid network on the distal side, wherein the additional grid network has a higher modulus of elasticity in comparison to that of the flexible grid network. The stem component is inserted into a cavity in the bone and has an enveloping adapter. A tube or socket is glued to the implant stem. An enveloping sheath in the form of bellows is attached to a collar on the tube or socket providing flexibility. The bottom portion of the bellows is attached to an open cell grid with apertures for attaching the skin. The skin attachment is not load transferring with the bone attachment due to the presence of pleated bellows, which inherently generates relative movement between the bone and the skin. Moreover, there is no porous or open mesh material in direct contact with the bone of the femur. There is also no direct attachment of the open mesh grid and the implant stem.
U.S. Pat. No. 6,869,450 and Foreign Patent Application No. DE 19931882 C1 to Grundei disclose a subcutaneous, intramuscular support for a rigid transcutaneous implant. This subcutaneous, intramuscular support is provided for a rigid transcutaneous implant, which can be anchored intracorporeally in a bone stump. The support has an intermediate piece between the part of the implant to be intracorporeally anchored and an extracorporeal coupling device that can be coupled to it. A rigid bushing is firmly connected with the intermediate piece, such that an annulus is formed between the wall of the bushing and the intermediate piece, the annulus being closed in the intracorporeal direction, and into which annulus the extracorporeal coupling device can be inserted. A tube made of a flexible material is applied to the outer wall of the bushing, and a metallic wool is applied to the flexible tube. The stem component is inserted into a cavity in the bone and has a metal sleeve with a conical clamping sleeve. An intermediate piece is force fitted into the implant stem. A flexible bushing with silicone collar and metallic mesh flexible collar is attached to the intermediate piece. The bottom portion of the flexible bushing is attached to a open cell grid with apertures for attaching the skin. The skin attachment is not load transferring with the bone attachment due to the presence of pleated bellows, which inherently generates relative movement between the bone and the skin. Moreover, there is no porous or open mesh material in direct contact with the bone of the femur. There is also no direct attachment of the open mesh grid and the implant stem.
U.S. Pat. No. 7,014,661 to Blunn et al. discloses a transcutaneous prosthesis. The transcutaneous prosthesis comprises a first component shaped for implantation into a bone, a second component intended for location between the bone and the skin, and a third component intended for location exterior to the skin surface, having a low surface energy, which deters bacterial adhesion. The prosthesis has three discrete components. The first component has longitudinally extending flutes that engage with the bone. The surface of the first component may be coated with apatite or micropitted, There is no indication that the material used is a biocompatible titanium or cobalt chromium alloy. The second component is cylindrical and extends from the first component. It is also coated with a surface treatment to attach to the bone. This surface treatment is not indicated to be a porous coating of any nature. The attachment to soft tissue is to be carried immediately during surgery or wait until the bone healing is complete. The attachment to skin is by using alumina oxide or apatite. However, there is no attachment between any of these coating materials and the stem, in particular, the skin which contacts loose aluminum oxide or apatite.
U.S. Pat. No. 7,018,420 to Grundei discloses a subcutaneous, intramuscular bearing for a rigid transcutaneous implant. The subcutaneous, intramuscular bearing for a rigid transcutaneous implant is provided, for anchoring intracorporally in a bone stump. The bearing has an intermediate piece between the implant and an extracorporal coupling for coupling on the implant. A rigid bushing is tightly connected to the intermediate piece, such that between the wall of the bushing and the intermediate piece an annular space is formed, which is closed in the intracorporal direction, for receiving and setting the extracorporal coupling. The outer wall of the bushing has an open-meshed, three-dimensional lattice structure and a lattice-free distal region having a width ‘B’. A spring ring is set in the annular space from the distal end, moved with a telescoping motion, and locked under exertion of its spring effect. This device has a stem with a flared end. The whole surface of the stem has a three-dimensional, open-meshed lattice structure designed for bone in-growth and tissue in-growth. After this initial attachment, a second piece is inserted which also has the three-dimensional, open-meshed lattice structure and is expected to attach to soft tissue. Since all the soft tissue is already used in the first stage of the operation, this second soft tissue attachment is not likely. Besides, the presence of a spring allows movement between two skin in-growth regions, creating skin stress.
Foreign Patent Application No. EP 1559383 to Grundei discloses a set for constructing a transcutaneous implant. A femur implant has an adapter for an exoprothetic standard component with a proximal shank. The shank has a three-dimensional open mesh structure. The shank distal end has a link-interface for the standard exoprothetic standard component. From the figure it appears that the stem is provided with open celled lattice for attachment within the one canal. Presence of the open celled lattice in the bottom portion indicates that there is bone attachment in more than one place. There appears to be a hinge provided within the stem. And a prosthesis may be attached at the distal end. There appears to be no soft tissue attachment. If any soft tissue attachment occurs in the distal bottom end, as indicated by the open celled lattice, the skin will be highly stretched.
There remains a need in the art for a percutaneous implant for humans and animals (i) that is capable of being attached to a broken or amputated bone; (ii) that successfully attaches the implant to both bone and soft tissue; (iii) that provides a natural extension of the amputated limb; and (iv) that comprises a skin attachment which prevents entry of infectious microorganisms. The percutaneous implant carries one of several prosthesis.